- Source: 1921 Dover by-election
- Britania Raya
- 1921 Dover by-election
- Dover, Massachusetts
- 1921 Abingdon by-election
- 1921 Penistone by-election
- 1921 Hertford by-election
- 1921 Bewdley by-election
- 1921 Bedford by-election
- 1921 Caerphilly by-election
- List of ministerial by-elections to the Parliament of the United Kingdom
- 1921 Westhoughton by-election
The 1921 Dover by-election was held on 12 January 1921. The by-election was held due to the succession to the peerage of the incumbent Coalition Unionist MP, Vere Ponsonby as Ninth Earl of Bessborough. It was won by the Independent candidate Thomas Andrew Polson.
Polson's election was supported by Horatio Bottomley, but although claimed by Bottonmley as a member of the right-wing Independent Parliamentary Group, he joined the Anti-Waste League shortly after his election. Polson stood again at the general election in November 1922, but was defeated by the Unionist candidate John Jacob Astor, whom he had defeated at the by-election in 1921.